258. Botany. 
ever, be most entitled to confidence. Dr. Bigelow, in his 
paper on this subject, an abstract of which was given in the 
ist No. of this Journal, selected the Peach-tree, from the 
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sirable to prosecute the subject, and that several trees 
should be observed at each place, and at the same stage of 
flowering. ‘The last particular appears very important. For 
rom the conclusion of Dr. Bigelow, it will be seen, that a 
difference of about four days, corresponds to a difference of 
one degree of latitude. Observers may be expected to 
differ at least two days in the time that a tree may be thought 
to be fully in bloom. 
have made these obvious remarks, because they pre- 
sent some of the difficulties in obtaining very definite and 
conclusive results upon climate from the flowering of plants, 
unless there be very accurate and continued observations ; 
and, I have made them in this place, because they were con- 
nected with the immediate object. Whether these difficul- 
ties be considered as great as they appear to me, the con- 
clusion 'to be drawn from the observations upon the last four 
years in Sa to a late or an yam f autumn, will not be es- 
sentially affect 
Williams Calves, April, 1820. 
ZN 
FOR THE AMERICAN JOUR. OF ‘SCIENCE. ; 
Arr. X. On the manufacture of Sugar from the River Ma- 
“ ts (Acer eriocarpum, of Linnaus 3) by Dr. Jou 
OCKE. 
T seems not to be generally known, that sugar is rect 
cay in any considerable quantity, by any oi see 
the sugar maple, (Acer saccharinuin ;) bait T have Pound ‘ht 
in some parts of New-England, more sugar is made from 
the river, than from the sugar maple. 
The facts I have uséoriaiied: with regard to the ma- 
king of sugar from the river maple, I collected in Fryeburg; 
(Me. ) on the Saco river, where large quantities are annually 
made ; but before I state them, I will give some account of 
the tivo species, the sugar and river maple. 
